If not piston deployment, then what???

What?!? You have to clean them out?

Just joking, you reminded me to clean mine out before the season starts.

And gets clogged with ejection caps.

Good for kit sales.

Jerry

For you, EVERYTHING is about Jerry.

Grasshopper Piston rocket fliers fall into 2 categories

2- Those who "will have" a piston failure.

Experienced fliers fly recognize the categories above and choose to fly with chute protectors and shock cord protectors.

Bobby B

Screw Jerry. I do not even know how he got into this thread.

you're right about that.

I don't often use stainless mesh in my baffle systems. but when I do I make sure it is removeable & cleanable/replaceable.

Only gets clogged if you IGNORE the instructions....

The mesh needs to be removed after a few flights " fluffed" and reinstalled. takes a min or so.... NO BIG DEAL...

I have 7 Aerotech rocekts using this system and they ALWAYS open.... mesh holds up fine.....

Bobby B

If you have a failure, it is generally due to not checking clearances in warm and cold weather, or failing to perform an inspection of your nylon tether.

And curiously, I don't recall anybody asking for facts, but instead opinions. But as in most cases in these threads, all the rocket scientists have to add their comments.

Thanks Tweaky, you have enlightened me.

Where do you get this material?

Mike wrote:

I get mine from LOC . their nomex blankets are nice and smooth so easy to slide in the muzzle, err parachute tube.

I use sizes or or two times larger then recomened to cover the whole chute

Yeah. Wanna know what is most about Jerry in my life? - When I flush the toilet. (Hope I haven't started an Anti Abortion discussion)

It's more like -

2- Those that can't deal with one extra step in their preflight check.

I assume you mean the shear pins. I use 2-56 nylon screws.

How did I do?

I just can't believe everybody is actually debating ROCKETRY content.

shhhhh.

I just find pistons to add several failure modes that do not exist without them.

Yes there are some cool aspects to pistons and OF COURSE with ALL the proper preventative measures they are essentially 100% reliable.

But stuff happens.

Launch fever happens.

Weather changes happen.

Pistons have issues that add failure modes.

Baffles do not.

Jerry

Experience since the mid-80's!

Don't worry, jerry is still the king.

I've noticed a lot of the poor opinions relating to piston ejection comes from people with failures but none from people that are consistently successful. In other words I've never noticed someone say I use it successfully over and over but I still don't trust it and I've done away with it.

Leads me to believe that the failures may be due to incompetence in construction or negligence in maintainance and not the design of the recovery system. When you factor this into the equation, who's opinion is to be trusted? Someone who can't build and fly and/or is too lazy or forgets to clean a tube after a flight or someone who follows manufacturers recommendation and has never had a problem directly attributable to a piston ejection failure.

PML seems to sell quite a few rockets with this system and if it didn't work I'm sure they would have removed it from their design, their sales would have dictated it.

For the record I have two different PML rockets with this design and used them to certify Level 1 and 2 and each flight was perfect. I used them because I figured the odds were much better having a piston push out the chute versus relying on just the ejection charge to deploy the chute. I've seen too many stuck chutes in my time so I was very wary of depending on this option for a cert flight and I wanted those chutes out and opening up for a nice soft landing so I used the piston.

Andrew

Gezunheidt!

Opps...wrong thread :-)

John